Remember that your audience is the broader scientific community, not the other students in your class or your professor.Therefore, you should assume they have a basic understanding of psychology, but you need to provide them with the complete information necessary for them to understand the research you are presenting.Be careful about citing your sources (see APA manual).
No more than 120 words, one paragraph, block format (i.e., don’t indent), double-spaced. Provide overview of method, results, and discussion. Although you won’t go into the details of your study and hypotheses until the end of the intro, you should foreshadow your study a bit at the end of the first paragraph by stating your purpose briefly, to give your reader a schema for all the information you will present next.
Note that in some studies (e.g., questionnaire studies in which there are many measures to describe but the procedure is brief), it may be more useful to present the Procedure section prior to the Materials section rather than after it. (e.g., money, extra credit points) Write for a broad audience. 280...” Rather, write (for instance), “Students in a psychological statistics and research methods course at a small liberal arts college….” Try to avoid short, choppy sentences.
Total number of participants (# women, # men), age range, mean and SD for age, racial/ethnic composition (if applicable), population type (e.g., college students). Combine information into a longer sentence when possible.
When an idea is complex, don’t be afraid to use a real-life example to clarify it for your reader.
The introduction will end with a brief overview of your study and, finally, your specific hypotheses.